In that original application a unique valve for a viscous product contained by a squeeze bottle is disclosed as comprising, among other things, a base formed by a circular rim, a circular wafer and spokes connecting with and radiating from the wafer's bottom and extending radially to the rim in a plane below that bottom and positioning the wafer on and normal to the rim's axis. This wafer has a small diameter as compared to the rim's diameter so an annular open sapce is formed between the wafer and rim. Combined with this, there is a cap comprising an elastically flexible annular diaphragm positioned above the plane extending from the wafer's bottom and having a central opening with a periphery normally resting on the periphery of the wafer, and a depending flange connected to the rim of the base. The peripheries of the diaphragm's central opening and of the wafer have substantially mating conical surfaces.
This contrasts with the prior art in that no projection extends upwardly from the hub of the spokes, the latter being thin and mounting the wafer only by its bottom so that the wafer, in effect, floats stationarily in open space. When a viscous product is squeezed against the bottom of the diaphragm, it deflects upwardly so that the two peripheries separate. When the two peripheries return together, the product is free to flow from the mating conical surfaces so they close easily and provide a positive shut-off.
To promote the above positive shut-off, the wafer is made very thin with a flat top and bottom, the spokes having upstanding inner tips which connect with that bottom only adjacent to the wafer's periphery, in effect leaving the wafer's entire surface free from obstructions in any direction.
Before that new valve could be put into production and sale, and apparently because of the inability of prior art valve constructions to handle viscous products while being capable of manufacture, the industry concerned with the production and sale of packages containing viscous products, retrogressed and extensively readopted the old so-called roll-on form of dispensing device. This is the one comprising a rotating ball mounted in the top of the container usually made of rigid material as exemplified by rigid plastic or glass. The ball rolled on the viscous product by acting like the ball of a ball-point fountain pen. This construction does have the advantage that it provides the user with a rounded or ball-like applicator surface which is particularly popular in the case of roll-on deodorants for underarm use. It has the disadvantage that there is no real valve action involved, a cap being necessary to prevent excessive leakage in case this type of dispensing package is inverted for any length of time. In addition, the amount of material that can be carried from the surface of the ball rotating in the viscous material, onto the outside of the ball for application use, is uncontrollable. The material carried on the outside of the rotating ball is entirely dependent on the adhesive characteristics of the viscous product with respect to the ball's surface. Another disadvantage is that the ball must be made to fit with relative precision in its socket which is attached to the product container, which makes the manufacture of this type of device undesirably expensive.
In the present instance, the object has been to provide a squeeze bottle valve which handles viscous products as effectively as does the valve of the above-identified application, but which will provide an external contour that is dome-shaped and to which the product is extruded by the valve so it spreads over the surface as in the roll-on type of device, but under the control of the user by controlled squeezing of the squeeze bottle.